Recirculating air

[Gerita]

We have an air advisory alert of 408!! in my area because of the Canada wildfires this week. I want to run our cooling system to recirculate air while cooling rather than pulling it from outdoors for fear our house will smell like the thick smoke outside. 
I have researched as best I can but don’t find info on if this is possible with the Nest learning thermostat— or I am I to ‘assume’ that if I run just the fan, it will not draw outside air into the system?

thank you for any help!

[Roseannerd]

I live in Buffalo and having the se air quality issue. I have been setting my Nest to fan only mode to recirculate the air without bringing in the smokey air and it works fine! 

[ZJ1]

I'm  further south  where the temp is in upper 80s so I still need to cool the house, but still dealing with the hazardous Air Quality from the Canada Forest fires.  Can I run the AC w/o bringing in outside air or is the only way not to bring in outside air is run in FAN Only mode?

[Markjosephp]

Hello folks,

I'm sorry for the late reply. I know it has been a while, but I wanted to ensure that everything was covered here. 

I did find a helpful article about the Fan control with the Nest Thermostat. The fan wire in most Nest Thermostats is used primarily for recirculation purposes. However, many people don’t use the recirculate feature when using their thermostats. This is because the fan turns on automatically when the heat and AC are on. Select the Fan Schedule to have your fan come on to circulate air in your home. Take note: the Nest Thermostats don't have the ability to control the airflow, depending on your system, but other systems have a manual switch to close the intake from the outside air.

Let us know if you have more questions.

Regards,

Mark

[Jenelyn_O]

Hi everyone, 

I appreciate the help, Mark.

@Gerita, @Roseannerd, and @ZJ1, I just want to check if you managed to see the response above. Please let us know if you still have questions or concerns, as we'll be willing to assist you further. 

Best,

Jenelyn

[Markjosephp]

Hey there,

I'm checking in to make sure that you've seen our response. Please let us know if you have any additional questions or concerns before we close this thread in 24 hours. 

Thanks,

Mark